Birth weights of fetuses exposed to diagnostic ultrasound

The birth weights of newborns routinely subjected to diagnostic ultrasound antenatally are compared with the birth weights of infants delivered by the same physician over a similar span of time seven years earlier, when diagnostic ultrasound was not available. They are also compared with the birth weights of infants delivered by a physician in the same rural community who requested diagnostic ultrasound for less than 10 per cent of his pregnant patients. There is no apparent difference between the average weights of the infants subjected to diagnostic ultrasound and those who were not.